ESTRO 2025 - Abstract Book

S1376

Clinical - Lung

ESTRO 2025

2889

Digital Poster PRIMALung (EORTC-1901) preliminary data: PRophylactic cerebral Irradiation (PCI) or active brain MRI surveillance in SCLC patients Antonin LEVY 1,2 , Thierry Berghmans 3 , Michael Koller 4 , Beatrice Fournier 5 , Murielle Mauer 5 , Nicolaus Andratschke 6 , Corinne Faivre-Finn 7 1 Radiation Oncology, Gustave Roussy, Villejuif, France. 2 3. Faculté de Médecine, Université Paris Saclay, Le Kremlin Bicêtre, France. 3 4. Thoracic Oncology, Institut Jules Bordet, Brussels, Belgium. 4 5. Centre for Clinical Studies, University Hospital Regensburg, Regensburg, Germany. 5 EORTC HQ, EORTC, Brussels, Belgium. 6 Radiation Oncology, University Hospital Zurich, Zurich, Switzerland. 7 8. The Christie NHS Foundation Trust, University of Manchester, Manchester, United Kingdom Purpose/Objective: PCI has been used to reduce the incidence of brain relapse and improve overall survival (OS) in patients with small cell Lung cancer (SCLC) but brain MRI could allow for earlier detection of asymptomatic metastases. The PRIMALung trial aims to determine if brain MRI surveillance alone is non-inferior to PCI combined with brain MRI surveillance in the immunotherapy era [1].

Material/Methods:

Participants must be 18 years or older with confirmed all stage SCLC and have completed standard treatments, including platinum-based chemotherapy and thoracic radiotherapy or surgery for limited-stage (LS), or at least three cycles of chemotherapy for extensive-stage (ES). They must show no disease progression on imaging and an ECOG performance status (PS) <2, with no limit of age. Participants are randomized 1:1 to receive either brain MRI surveillance +/- PCI, stratified by disease stage, immunotherapy use, ECOG performance status, and country. Brain